CN111623253B

CN111623253B - LED filament lamp with V-shaped geometry

Info

Publication number: CN111623253B
Application number: CN202010131084.8A
Authority: CN
Inventors: J·J·李; A·杜塔
Original assignee: Osram Sylvania Inc
Current assignee: Osram Sylvania Inc
Priority date: 2019-02-28
Filing date: 2020-02-28
Publication date: 2022-08-12
Anticipated expiration: 2040-02-28
Also published as: DE102020105190A1; US10928012B2; US10605413B1; CN111623253A; DE102020105190B4; US20200278088A1

Abstract

The application discloses a light emitting diode filament lamp having a V-shaped geometry, wherein a light engine comprises: electrical leads extending into the support stem; and a filament assembly having a V-shaped geometry electrically connected to the electrical leads, comprising at least two light emitting diode filaments, wherein a first end of the filament assembly is in electrical contact with the electrical leads and provides a tip of the V-shaped geometry, and a second end of the filament assembly opposite the first end has a second width greater than a first width of the tip; and a conductive path connecting the second ends of the at least two light emitting diode filaments.

Description

LED filament lamp with V-shaped geometry

Technical Field

The present invention relates generally to light engines employed in lamp assemblies, and more particularly to light engines employing light emitting diodes as light sources.

Background

Due to cost and environmental impact, there is an increasing concern about the conservation and management of electrical energy. In a number of different lighting applications, Light Emitting Diodes (LEDs) for illumination are beginning to emerge as illumination sources that may address these concerns. The LED light source has a long life, high energy efficiency, is durable, and can operate across a wide temperature range. While LED lighting is becoming attractive for some applications, it is not an optimal solution for many applications. Accordingly, there is a need for improved LED lighting systems.

Disclosure of Invention

On the one hand, the method and structure of the present invention improves the light distribution pattern of Light Emitting Diode (LED) light engines by providing a V-shaped geometry for the arrangement of the LED filaments, as compared to prior lamps employing filaments arranged in an inverted V-shaped geometry (sometimes referred to as a christmas tree geometry due to the inverted V-shape of state-of-the-art LED lamp filament light engines). The V-shaped geometry of the light engine of the present invention includes a base for assembly of the filament, which is connected to electrical leads extending into the support stem of the lamp, and a portion of the filament assembly having a smaller diameter that extends into the region of the optical element of the lamp opposite the stem.

In one embodiment, the invention provides a light engine that includes electrical leads extending into a support stem. The filament assembly is electrically connected to the electrical leads and includes at least two Light Emitting Diode (LED) filaments. The filament assembly has a V-shaped geometry, wherein a first end of the filament assembly provides a tip of the V-shaped geometry. The first end of the filament assembly is in electrical contact with the electrical lead. A first filament of the at least two light emitting diode filaments is electrically connected to the anode of the electrical lead and a second filament of the at least two light emitting diode filaments is electrically connected to the cathode of the electrical lead. A second end of the filament assembly opposite the first end has a second width greater than the first width of the tip portion. The conductive path connects the second ends of the first and second filaments of the at least two light emitting diode filaments.

In one embodiment, a lamp is provided that includes a lamp housing including a light projecting end and a lamp head having an electrical connector for connecting to a lamp holder, and a light engine including a Light Emitting Diode (LED) positioned at the light projecting end of the lamp housing. The light engine includes electrical leads extending into the support stem. The filament assembly is electrically connected to the electrical leads and includes at least two light emitting diode filaments. The filament assembly has a V-shaped geometry, wherein a first end of the filament assembly provides a tip of the V-shaped geometry. The first end of the filament assembly is in electrical contact with the electrical lead. A second end of the filament assembly opposite the first end has a second width greater than the first width of the tip portion. The conductive path connects the second ends of the first and second filaments of the at least two light emitting diode filaments. The driver assembly is in electrical communication with the electrical connector of the base of the lamp envelope and the electrical lead to the light engine. The driver assembly is located in the lamp housing.

In another aspect of the invention, a method of assembling a lamp is provided that includes connecting a filament assembly to a support stem of the lamp. The stem includes a mandrel and an electrical lead. The filament assembly includes at least two light emitting diode filaments, each filament including a connecting conductive path from the second end of each of the at least two light emitting diode filaments to the slip ring. The mandrel is positioned between the anode and the cathode of the electrical lead. Connecting the filament assembly to the support stem comprises electrically connecting a first end of a first of the at least two light emitting diode filaments to the anode and electrically connecting a first end of a second of the at least two light emitting diode filaments to the cathode, with a central axis located within the opening of the slip ring. A cap is placed over the mandrel and over the slip ring. The filament assembly connected to the stem is then inserted into the open end of the optical element, and a cap above the slip ring contacts the dome portion of the optical element, wherein the cap presses down on the slip ring to slide the slip ring down on the mandrel as the stem is brought to its seated position. The sliding down slip ring pushes the connecting conductive path electrically connected to the second ends of the at least two light emitting diode filaments away from the mandrel. First ends of the at least two light emitting diode filaments are substantially fixed adjacent to the mandrel. A second separation width at the second end of the at least two light emitting diode filaments is greater than the first separation width at the first end of the at least two light emitting diode filaments such that the at least two light emitting diode filaments are arranged in a V-shaped geometry when the stem is in its seated position.

Drawings

The following description provides details of embodiments in conjunction with the accompanying drawings, in which:

fig. 1 is a side cross-sectional view of a filament assembly according to an embodiment of the invention comprising at least two light emitting diode filaments arranged in a V-shaped geometry within the optical element of the lamp, wherein the ends of the filaments opposite to the end thereof connected to the stem are connected by a ring-shaped conductive path, the ring surrounding the mandrel of the stem.

Fig. 2A-2C are perspective views of a light emitting diode filament according to an embodiment of the invention.

Fig. 3 is a side cross-sectional view of another embodiment of a filament assembly comprising at least two light emitting diode filaments arranged in a V-shaped geometry within the optical element of the lamp, wherein the ends of the filaments opposite to the end connected to the stem are connected by conductive vias passing through the mandrel of the stem.

Fig. 4 and 5 are side cross-sectional views of a further embodiment of a filament assembly comprising at least two light emitting diode filaments arranged in a V-shaped geometry within the optical element of the lamp, wherein the ends of the filaments opposite to their ends connected to the stem are connected by a ring-shaped conductive path, the ring surrounding the mandrel of the stem, and further mechanical support being provided by metal leads passing through the mandrel of the stem connecting the opposite filaments.

Fig. 6 is a side perspective view of a filament assembly including at least two light emitting diode filaments for a light engine of a lamp, wherein the filament assembly is of a geometry having an overall width that can be inserted through an opening of a lamp optic during lamp assembly.

Fig. 7 is a side cross-sectional view of an optical element of a lamp according to an embodiment of the invention, wherein a filament assembly is mounted within the optical element such that the filament assembly includes at least two light emitting diode filaments arranged in a V-shaped geometry.

Fig. 8 is a graph illustrating a comparison of luminous intensity distributions from a light engine test sample having a light emitting diode filament arranged in a V-shaped geometry as compared to a light engine comparative example having a light emitting diode filament arranged in an inverted V-shaped geometry, which is state of the art.

Fig. 9 shows the angle of the lamp, which is defined for measuring illumination by goniometry.

Fig. 10 is an exploded view of a lamp including a filament assembly having at least two light emitting diode filaments arranged in a V-shaped geometry according to one embodiment of the invention.

Fig. 11 is a perspective view of a lamp including a filament assembly having at least two light emitting diode filaments arranged in a V-shaped geometry according to one embodiment of the invention.

Detailed Description

Reference in the specification to "one embodiment" or "an embodiment" and other variations thereof means that a particular feature, structure, characteristic, and so forth described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" and any other variations in various places throughout this specification are not necessarily all referring to the same embodiment. As used herein, "direct electrical contact" refers to electrical communication across a physically conductive medium, such as a wire. The term "electrical communication" refers to energy transfer, i.e., power transfer or electrical current, but does not require direct contact between the elements in electrical communication.

In some Light Emitting Diode (LED) filament lamps, the filament is arranged such that the effective diameter of the circle formed by the top of the filament, i.e., the portion closest to the upper dome of the optical element (also referred to as the bulb), is smaller than the diameter formed by the bottom of the filament, i.e., the portion closest to the electrode for communication with the lamp holder. In other words, the filament is arranged in a conical geometry, appearing like an inverted V, with the diameter of the base of the lamp tap being greater than the diameter of the tip.

The structures and methods of the present invention provide light engines that include Light Emitting Diode (LED) filaments arranged in geometries that will enable improved light distribution patterns that are not possible with existing inverted V-shaped geometries. The light engine of the present invention employs Light Emitting Diode (LED) filaments arranged in a V-shaped geometry, as opposed to an inverted V-shaped geometry. In some embodiments, a new geometry for the LED filament layout, i.e., a V-shaped geometry, may be used in the decorative filament lamp. The method and structure of the present invention will now be described with reference to fig. 1-11.

Fig. 1-7 show some embodiments of

filament assemblies

100a, 100b, 100c, 100d, 100e comprising at least two Light Emitting Diode (LED)

filaments

50a, 50b arranged in a V-shaped geometry within an optical element 75 of the lamp, wherein the ends of the

filaments

50a, 50b opposite to the end thereof connected to the stem 25 are connected by electrically

conductive paths

55, 55a, 55b, 55 c. In the embodiment shown in fig. 1, the conductive path 55 is annular in shape to the mandrel 30 surrounding the stem 25.

Light Emitting Diodes (LEDs) are in the form of solid state light emitters. The term "solid state" refers to light emitted by solid state electroluminescence, as opposed to incandescent bulbs (which use thermal radiation) or fluorescent tubes (which use a low pressure Hg discharge). In a broad sense, a Light Emitting Diode (LED) is a semiconductor device that emits visible light when an electric current passes through it. Some examples of solid state light emitters suitable for the methods and structures described herein include inorganic semiconductor Light Emitting Diodes (LEDs), surface mount light emitting diodes (SMT LEDs), or combinations thereof.

In some embodiments, the Light Emitting Diodes (LEDs) employed in the

light engines

100a, 100b, 100c, 100d, 100e are Light Emitting Diode (LED) filaments. Referring to fig. 2A-2C, the substrate 28 of each Light Emitting Diode (LED)

filament structure

50a, 50b includes a plurality of series-connected Light Emitting Diodes (LEDs) 29 present on the substrate 28 and extending from the cathode contact 27 to the anode contact 26.

Fig. 2A shows an embodiment of a substrate 28 positioned between an anode contact 26 and a cathode contact 27. In some embodiments, substrate 28 may be a transparent substrate, which may be made of glass such as silicon (Si) and/or silicon dioxide (SiO) ₂ ) Or sapphire such as alumina (Al) ₂ O ₃ ) And (4) preparing. This transparency enables the emitted light to be spread evenly without any interference or light loss. In some other embodiments, substrate 28 may be a metal strip. It should be noted that although fig. 2A-2C illustrate an LED filament having reference numeral 50a, the description of the LED filament illustrated in fig. 2A-2C is equally applicable to the LED filament having reference numeral 50b described herein. In some embodiments, the substrate 28 shown in fig. 2A may be referred to as a first layer of the

LED filaments

50a, 50 b.

Referring to fig. 2B, in some embodiments, each Light Emitting Diode (LED) filament structure 50a includes LEDs 29 (also referred to as LED dies) arranged in rows on a small bar. The number of LED dies 29 on any filament can be 10 or more. In one example, the number of LEDs 29 disposed on the substrate 28 of the Light Emitting Diode (LED) filament structure 50a may be 10 to 50 LEDs. In another example, the number of LEDs 29 disposed on the substrate 28 may be 15 to 40 LEDs. In yet another example, the number of LEDs 29 disposed on the substrate 28 may be 20 to 30 LEDs. The LEDs 29 on the substrate 28 may be electrically connected in series and extend from the cathode contact 27 to the anode contact 26. In the embodiment shown in fig. 2B, the LEDs 29 may be interconnected in series using connecting wires by a process commercially known as wire bonding.

In one exampleThe LED 29 is an unpackaged LED die. The LED 29 and the connection elements providing the series connection may be referred to as a second layer of the filament LED, which is present on top of the substrate 28. The LED die 29 may be formed of In _x Ga _y N _z Wherein x, y and z refer to different stoichiometric compositions. The form factor of the die of the LED 29 may be 1128, 0922, 0815, 0714, 0627, or less. The first two and the last two are die sizes (thousands of inches). This list is by no means an exclusive list and other form factors are within the scope of the invention.

Fig. 2C shows an embodiment of a phosphor coating 31 present over the LED 29. In one example, the filament strip, i.e., the LED 29 on the substrate 28, emits blue light. For example, blue light emitted by the filament strip of LED filament 50a, i.e., LED 29 on substrate 28, may have a wavelength from about 430nm to 470 nm. To provide "white light," a phosphor coating 31 in a silicone adhesive material may be placed over the LEDs 29 to convert the blue light generated by the LEDs 29. White light is not one color, but a combination of all colors, and therefore, white light includes all wavelengths from about 400nm to 700 nm. Different chemical compositions and properties of the phosphor coating 31 may be used to change the color of the light emitted by the LED 29. A typical phosphor chemistry used is cerium doped yttrium aluminum garnet. The phosphor converts blue light to yellow light. When unconverted, the blue light from the die combines with the yellow light from the phosphor, creating the perception of white light by the brain. In some embodiments, the phosphor coating 31 shown in fig. 2C may be referred to as a third layer of the

filament LEDs

50a, 50 b.

Referring to fig. 1-7, the

LED filaments

50a, 50b may be 20mm (3/4 ") or more in length. In one example, each of the Light Emitting Diode (LED)

filament structures

50a, 50b may have a length on the order of 100mm (4 ") and a width on the order of 3mm (1/8"). In some examples, a filament LED lamp suitable for use with

light engines

100a, 100b, 100c, 100d, 100e may include a short filament, such as 20mm-40mm, and a long filament, such as 40mm-60 mm.

Referring to fig. 1-7, in some embodiments, the Light Emitting Diode (LED)

filament structures

50a, 50b emit white light having a color temperature ranging from 2700K to 6500K. In one example, the white light emitted by the

LED filament structures

50a, 50b may be referred to as "daytime white" having a color temperature ranging from 3800K to 4200K. In another example, the white light emitted by the Light Emitting Diode (LED)

filament structures

50a, 50b may have warm white light with a color temperature ranging from about 2600K to 3000K. It should be noted that the above examples are given for illustrative purposes only and are not intended to limit the present invention.

In some embodiments, Light Emitting Diode (LED)

filaments

50a, 50b are selected for decorative filament lamps. Decorative filament lamps may have a light emitting filament that emits in the red or green or blue (R-G-B) portion of the visible spectrum. The decorative lamp may have a colored glass bulb as a housing. The decorative lamp can also have a combination of colored light-emitting filaments and colored glass bulbs. The color light emitting filament has a suitable phosphor blend deposited on a blue emitting semiconductor die such that the combination of blue light from the die and light emitted by the phosphor blend results in substantially red or green or blue light emission. Generally, blue light is defined in this specification to include light of 400-500nm wavelength. The red light includes wavelengths of 600-700nm and the green light includes wavelengths of 500-600 nm. Blue, green, and red light wavelengths may be emitted by Light Emitting Diode (LED) filaments as described herein.

The

filaments

50a, 50b are arranged in

light engines

100a, 100b, 100c, 100d, 100e with a V-shaped geometry, wherein the part of the

filaments

50a, 50b closest to the burner 65, referred to as the "first" end of the

filaments

50a, 50b, has an electrical connector 66 for connection to a lamp holder. A first end of each filament is connected to an

electrical lead

76, 77 extending from the stem 25 of the

light engine

100a, 100b, 100c, 100d, 100e and provides a V-shaped geometry tip for the

light engine

100a, 100b, 100c, 100d, 100 e. The second ends of each

filament

50a, 50b are electrically connected to each other by a conductive path 55. The second end of each

filament

50a, 50b is opposite the first end of the respective filament, with the second end of the

filament

50a, 50b being closest to the uppermost portion of the dome of the bulb 75 when the

light engine

100a, 100b, 100c, 100d, 100e is installed in the lamp. To provide a V-shaped geometry, the separation width W2 of the second end of the opposing light emitting

diode filament

50a, 50b is greater than the separation width W1 of the first end of the opposing light emitting

diode filament

50a, 50 b. In one embodiment, the separation width W2 of the second end of the opposing light emitting

diode filament

50a, 50b may be 28mm to 50mm, and the separation width W1 of the first end of the opposing light emitting

diode filament

50a, 50b may be 4mm to 14 mm.

In some embodiments, the mandrel 30 extends longitudinally from the stem 25 and is located between opposing Light Emitting Diode (LED)

filaments

50a, 50 b. In some embodiments, the height of the mandrel 30 is substantially equal to the height of the Light Emitting Diode (LED)

filaments

50a, 50 b. To provide a V-shaped geometry, the separation width between the Light Emitting Diode (LED)

filaments

50a, 50b on either side of the mandrel 30 may increase from the base at a first end of the Light Emitting Diode (LED)

filaments

50a, 50b to the upper surface at a second end of the Light Emitting Diode (LED)

filaments

50a, 50b, with the taper determined by the taper angle α measured between one of the Light Emitting Diode (LED)

filaments

50a, 50b and the mandrel 30 at the first end of the Light Emitting Diode (LED)

filaments

50a, 50 b. In some embodiments, the taper angle α may be 2 to 45 degrees (relative to the mandrel 30), as shown in fig. 1 and 3-7. In another embodiment, the taper angle α may be 5 to 30 degrees (relative to the mandrel 30). In some examples, the taper angle α may be 5 °, 10 °, 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, and any angular range that includes one of the above-mentioned values as a lower limit and one of the above-mentioned values as an upper limit.

The taper angle a is measured from the first ends of the Light Emitting Diode (LED)

filaments

50a, 50b connected to

electrical leads

76, 77 extending from the stem 25. The glass stem 25 encloses electrical leads 76, 77 that lead in DC (direct current) from a driver (not shown) to the Light Emitting Diode (LED)

filaments

50a, 50 b. Fig. 1 and 3-5 show four

filaments

50a, 50b connected in a two-filament parallel and two-filament series (2P2S) configuration. For example, the at least two Light Emitting Diode (LED)

filaments

50a, 50b of the

light engines

100a, 100b, 100c, 100d may include a first set of Light Emitting Diode (LED) filaments 50a connected in parallel at a first end of the filament assembly to the anode of the electrical lead 76 on the first side of the mandrel 30 extending from the stem 25 and a second set of Light Emitting Diode (LED) filaments 50b connected in parallel at a first end of the filament assembly to the cathode of the electrical lead 77 on the second side of the mandrel 30 extending from the stem 25. First and second sets of Light Emitting Diode (LED)

filaments

50a, 50b are connected in series at a second end of the

filament assemblies

100a, 100b, 100c, 100d by

conductive paths

55, 55a, 55b, 55 c.

Although fig. 1 and 3-5 illustrate Light Engines (LEDs) 100a, 100b, 100c 100d having four Light Emitting Diode (LED)

filaments

50a, 50b, the invention is not limited to this number. There may also be two filaments, six filaments, etc.

The opposing

filaments

50a, 50b are electrically connected at the second end of the filaments, i.e., the top of the filaments, by

conductive vias

55, 55a, 55b, 55c, which may be provided by connecting wires in some embodiments. In some embodiments, the conductive path 55 has a circular geometry that may be connected to the second element of a Light Emitting Diode (LED) filament by a suitable connection method, which may include spot welding, as shown in fig. 1 and 4. The rings shown in fig. 1 that provide the conductive paths 55 may be composed of any suitable conductive material, such as nickel plated steel, aluminum, copper, and the like. Fig. 3 shows another embodiment of a filament assembly 100b comprising at least two Light Emitting Diode (LED)

filaments

50a, 50b arranged in a V-shaped geometry within the optical element 75 of the lamp, wherein first ends of the

filaments

50a, 50b are connected to the stem 25. In the embodiment shown in fig. 3, there are two sets of Light Emitting Diode (LED)

filaments

50a, 50 b. Two sets of Light Emitting Diode (LED)

filaments

50a, 50b are electrically connected by

conductive pathways

55a, 55b, with each linear wire extending from one LED filament across mandrel 30 to the opposite LED filament to connect their second ends.

In some embodiments, the

light engines

100a, 100b shown in fig. 1 and 3 have a cone angle α of 15 degrees or less. The taper angle α is such that the separation of the Light Emitting Diode (LED) filaments at the upper surface of the

light engines

100a, 100b is greater than the separation of the Light Emitting Diode (LED) filaments at the base of the

light engines

100a, 100b, where the base of the

light engines

100a, 100b provides the tip (top) of the V-shaped geometry of the

light engines

100a, 100 b. The V-shaped geometry of the Light Emitting Diode (LED) filament provides an enhanced light distribution pattern that is not possible with light engines having Light Emitting Diode (LED) filaments arranged in an inverted V-shaped geometry. For example, the new more uniform light distribution pattern provided by a light engine having Light Emitting Diode (LED) filaments arranged in a V-shaped geometry is particularly advantageous when employed in a lamp that emits decorative light, such as red or blue or green light, or any combination thereof.

Fig. 4 and 5 show a further embodiment of a filament assembly comprising at least two Light Emitting Diode (LED) filaments arranged in a V-shaped geometry within the optical element of the lamp, wherein the ends of the filaments opposite to the end connected to the stem are connected by an annular conductive path 55, the mandrel annularly surrounding the stem, and further mechanical support is provided by

metal wires

55a, 55b passing through the mandrel of the stem to connect the opposite filaments. In some embodiments, the metal leads 55a, 55b contact portions of the ring.

The V-shaped geometry of the

light engines

100a, 100b, 100c, 100d shown in fig. 1 and 3-5 provides a more uniform light distribution as compared to an inverted V-shaped geometry. However, in some embodiments, as shown in FIG. 4, when the V-shaped

light engines

100a, 100b, 100c, 100d of the present invention may be more enhanced (by providing a larger taper angle α of the V-shaped geometry relative to the longitudinal direction, i.e., the height of the mandrel 30, such that there is a larger diameter W2 at the top of the V-shaped geometry), it may be possible to direct more light toward the lower regions of the lamp. The lower region of the lamp refers to the angular space from about 135 degrees to 180 degrees or from-135 degrees to 180 degrees, as shown in fig. 9. By increasing the light in the lower region of the lamp, the light engine may provide more light to the floor. This will produce a desirable, enhanced disco effect for dance floors in bars, restaurants, etc., especially when the lamp is connected to a pulsed electrical driver. In some embodiments, the light for a disco-type application includes a flash of light.

Fig. 4 shows an embodiment 100c of a light engine with Light Emitting Diode (LED)

filaments

50a, 50b having an enhanced V-shaped geometry, wherein the taper angle a is selected to provide a wider upper separation dimension of the

filaments

50a, 50b, i.e. at the upper surface of the light engine, wherein the wider V-shaped geometry provides increased under-lamp illumination. The enhanced V-shaped geometry providing increased under-illumination has a cone angle a (also referred to as tilt angle) that is in excess of 15 and possibly 30 degrees large. Using the enhanced V-shaped configuration shown in fig. 4, increased lumens were measured in the 130/180/+135 degree region, which is the light directed toward the ground. Lighting with these characteristics is particularly suitable for floor lighting, such as dance floor lighting. Measurements of light engines with such geometries and cone angles a (e.g., cone angles a in excess of 15 degrees but less than 30 degrees) also show an increase in lumens towards the lamp top in the region of 30/0/+ 30. Increased lumens towards the lamp top may provide the advantage of minimizing the dark area of the lamp.

Referring to fig. 1 and 3-7, in some embodiments, the

light engines

100a, 100b, 100c, 100d, 100e described herein include a mandrel 30, which may be provided by a glass rod, centrally located in the

light engines

100a, 100b, 100c, 100d, 100e and embedded in the glass stem 25. In some embodiments, there is a button 31 on the top surface of the mandrel 30. Similar to the spindle 30, the button 31 may also be composed of glass. In the embodiment shown in FIG. 1, there is no physical connection between the ring providing the conductive path 55 and the mandrel 30, where a button is provided for this connection. Such a connection may be required, for example, when it is desired to increase the mechanical stability of the ring, as shown in fig. 4 and 5. In the embodiment shown in fig. 4 and 5, there are electrically

conductive leads

55a, 55b, 55c connecting the opposite ends of the ring. The wires may pass through a glass button 31 located on top of a glass mandrel 30 embedded in the stem 25. In the embodiment shown in fig. 3, the rings may be omitted, with the electrically

conductive paths

55a, 55b of the light engine 100b being provided by connecting wires that electrically contact the second ends of the opposing Light Emitting Diode (LED)

filaments

50a, 50b through the glass button 31 at the top of the mandrel 30.

Referring to fig. 1 and 3-7, the glass stem 25 is sealed to a glass bulb or optical element 75 which is evacuated of air through the exhaust port 24 and then backfilled with a suitable highly thermally conductive gas mixture. The glass stem 25 holding the support rod, i.e. mandrel 30, and thus the light engine, is sealed to the glass bulb (also referred to as optical element 75). The glass bulb 75 may be of any of a number of types of lamp shapes, such as A19, A21, G, BR, B, C, and the like. Air from the sealed bulb (optical element 75) is expelled through an exhaust port located in the stem 25. The sealed and evacuated bulb (optical element 75) may be backfilled with a suitable highly thermally conductive gas mixture through exhaust port 24 and then the tube (not shown) leading to exhaust port 24 is broken to produce a sealed glass bulb (optical element 75) containing the appropriate gas mixture and light engine.

In some embodiments, the stem 25 is composed of glass and includes two right angle electrical leads 76, 77. These electrical leads 76, 77 may be composed of nickel (Ni) plated steel or other suitable material. For example, the electrical leads 76, 77 may also be composite wires comprising an inner lead, Dumet (Dumet) wire (copper clad nickel iron wire) and an outer lead joined together in that order.

In another aspect, the

light engines

100a, 100b, 100c, 100d, 100e already described with reference to fig. 1, 3-7 are comprised in a lamp 500, as shown in fig. 10-11. Fig. 10-11 illustrate an embodiment of a lamp 500 that may include a housing containing a light projecting tip (present at the optical element 75) and a lamp head 65 having an electrical connector 66 for connection to a lamp holder; and a light engine 100' within the housing having at least two Light Emitting Diode (LED)

filaments

50a, 50b arranged in a V-shaped geometry projecting light through the light projection end. The light engine 100' shown in fig. 10 and 11 may be any of the

light engines

100a, 100b, 100c, 100d, 100e already described herein with reference to fig. 1, 3-7. This description is incorporated herein for the description of the light engine 100' of the lamp 500 described with reference to fig. 10 and 11.

As shown in fig. 10 and 11, the bulb-shaped lamp 500 is a bulb-shaped LED lamp that can be used in place of an incandescent electric lamp, in which a base 65 is attached to a transparent bulb 75. A light engine 100' comprising Light Emitting Diode (LED)

filament structures

50a, 50b is enclosed in a light bulb 75. The light engine 100' comprising Light Emitting Diode (LED)

filament structures

50a, 50b arranged in a V-shaped geometry is directly fixed to the stem 25, the stem 25 extending through the opening 71 of the light bulb 75 towards the interior of the light bulb 75. The stem 25 is in electrical communication with driver electronics, such as lighting circuitry 80, which is in electrical communication with the lamp base 65 for engagement with a lamp holder.

In some embodiments, the light bulb 75 is a hollow transparent member that encloses the light engine 100 'therein and passes light from the light engine 100' out of the lamp 500. In some embodiments, the bulb 75 is a hollow glass bulb made of quartz glass that is transparent to visible light. The bulb 75 may have a shape with one end being a closed sphere and the other end having an opening 71. In some embodiments, the bulb 75 is shaped such that a portion of the hollow sphere narrows while extending away from the center of the sphere, and the opening 71 is formed at the portion away from the center of the sphere. In the embodiment shown in fig. 10 and 11, the bulb 75 is in the shape of a type a (JIS C7710), which is the same as a common incandescent bulb. It should be noted that this geometry is provided for illustrative purposes only and is not meant to limit the invention. For example, the bulb 75 may be G-type, BR-type, or other types. The portion of the bulb 75 opposite the opening 71 may be referred to as a "dome portion of the optical element".

The light engine 100' is located within the light bulb 75 by being connected to the

lead wires

76 and 77 supported by the stem 25. The stem 25 is a pillar extending toward the inside of the bulb 75. In some embodiments, the stem structure 25 is located between the light engine 100' and the driver electronics 80. In some embodiments, the other end of the body of the stem 25 opposite the portion from which the

lead wires

76, 77 extend to the light engine 100' comprises a flared shape that conforms to the shape of the opening 71. The portion of the main body of the stem 25 formed in the flared shape may be connected with the opening 71 of the bulb 75 to close the opening of the bulb 75. In other embodiments, the flared shape of the stem 25 may engage a first surface of the lamp cap shell 65 and the light bulb 75, and may also contact a second, separate surface of the lamp cap shell 65, wherein a sealing structure is provided between the lamp cap shell 65, the light bulb 75, and the flared end of the stem 25. In addition, portions of the two

lead wires

76 and 77 may be partially sealed in the stem 25. Thus, power may be supplied to the light engine 100' in the light bulb 75 from outside the light bulb 75, keeping the light bulb 75 airtight. Thus, the bulb-shaped lamp 500 may prevent water or water vapor from entering the bulb 75 for a long time, possibly inhibiting degradation of the light engine 100' and the portions connecting the light engine and the

leads

76, 77 due to moisture.

The lamp 500 may also include a light stem 25 that includes positive and negative leads, i.e., leads 76, 77, connected to a first end of a Light Emitting Diode (LED) filament of the light engine 100'. The stem 25 may be made of soft glass transparent to visible light. The structure of the bulb-shaped lamp 500 suppresses loss of light from the light engine 100' by the stem 25. In addition, the bulb-shaped lamp 500 may be prevented from being projected by the stem 25. In addition, light emitted by the light engine 100' may illuminate the stem 25. In addition to providing current to the

LED filaments

50a, 50b of the light engine 100 ', the two leads 76, 77 also support the light engine 100 ' and maintain the light engine 100 ' in a constant position within the light bulb 75.

Referring to fig. 10 and 11, in one embodiment, driver electronics 80, such as lighting circuitry, is circuitry that causes the LEDs of the multiple Light Emitting Diode (LED)

filament structures

50a, 50b to emit light, which is enclosed in a lamp cap shell 65. More specifically, the driver electronics 80, such as a lighting circuit, includes a plurality of circuit elements and a circuit board on which each circuit element is mounted. In this embodiment, driver electronics 80, such as lighting circuitry, converts AC power received from the burner 66 of the burner housing 65 to DC power and supplies the DC power to the LEDs of the plurality of Light Emitting Diode (LED)

filament structures

50a, 50b via two leads 76, 77. In an embodiment, the driver electronic circuit 80 is a lighting circuit, which may include a diode bridge for rectification, a capacitor for smoothing, and a resistor for regulating current. The lighting circuit is not limited to the smoothing circuit, but may be an appropriate combination of a light adjusting circuit, a booster, and the like.

The driver electronic circuit 80 may be enclosed within a lamp cap housing 65 composed of a resin material. The base shell 65 may be provided at the opening 71 of the bulb 75. More specifically, the cap shell 65 is attached to the bulb 75 using an adhesive such as a cement to cover the opening 71 of the bulb 75. The base 66 is connected to the end of the base shell 65 opposite the end closest to the bulb 75. In the embodiment shown in fig. 10 and 11, the lamp head 66 is an E26 lamp head. The bulb-shaped lamp 500 may be connected to a lamp socket for an E26 lamp cap and connected to a commercial AC power source. It should be noted that the lamp head 66 need not be an E26 lamp head, but may be other sized lamp heads, such as E17. Further, the base 66 does not have to be a screw base, but may be a base of a different shape such as a plug-in base.

It is also within the scope of the present invention to connect the new geometry light engine 100' to an electronic driver 80 that provides electrical power to the Light Emitting Diode (LED)

filaments

50a, 50b in a pulsed manner. More specifically, an electronic driver 80 located in the E26/E27 light head of the light 500, such as the light head housing 65, may be used which pulses DC (direct current) to the

LED filaments

50a, 50b causing the light to flash to create an entertainment effect useful for disco bar lighting. The electronic driver 80 is designed to cause the light engine 100' to flash at a frequency of about 1Hz to 3 Hz. In other words, in this mode of operation, the lamp will flash once for about 1 second to 3 times for about 1 second.

Fig. 6 and 7 illustrate some methods for assembling the V-shaped light engine 100e into a lamp structure. The light engine 100e comprising at least two light emitting

diode filaments

50a, 50b arranged in a V-shaped geometry may be any of the

light engines

100a, 100b, 100c, 100d already described with reference to fig. 1-5. The corresponding description is incorporated herein for describing the light engine 100e in the lamp structure assembly method described with reference to fig. 6 and 7. Fig. 6 is a light engine 100e prior to assembly into the glass bulb, i.e., optical element 75, of a lamp 500. Fig. 7 is a light engine 100e after assembly into a glass bulb, i.e., optical element 75.

In one embodiment, the method of assembling the lamp 500 includes connecting the filament assembly of the light engine 100e to the support stem 25 of the lamp 500, wherein the stem 25 includes a mandrel 30 and

electrical leads

76, 77 extending from the stem 25 on either side of the mandrel 30, as shown in fig. 6. In one embodiment, the filament assembly 100e shown in fig. 6 includes at least two Light Emitting Diode (LED)

filaments

50a, 50b, each filament including a connecting

conductive path

55a, 55b from a second end of each of the at least two Light Emitting Diode (LED)

filaments

50a, 50b to the slip ring 40. In some embodiments, connecting the filament assembly 100e to the support stem 25 includes electrically connecting first ends of at least two Light Emitting Diode (LED)

filaments

50a, 50b to

electrical leads

76, 77 of the stem 25, with the central axis 30 located within the opening of the slip ring 40.

In the embodiment shown in fig. 6, the number of Light Emitting Diode (LED)

filaments

50a, 50b is equal to 4. In some embodiments, a first set of at least two Light Emitting Diode (LED) filaments 50a are electrically connected to the anode of electrical lead 76, and a second set of at least two Light Emitting Diode (LED) filaments 50b are electrically connected to the cathode of electrical lead 77. In the embodiment shown in fig. 6, the at least two Light Emitting Diode (LED) filaments include a first set of Light Emitting Diode (LED) filaments 50a connected in parallel at a first end of the filament assembly 100e to the anode of the electrical lead 76 extending from the stem 25 on a first side of the mandrel 30, and a second set of Light Emitting Diode (LED) filaments 50b connected in parallel at a first end of the filament assembly 100e to the cathode of the electrical lead 77 extending from the stem 25 on a second side of the mandrel 30, the first and second sets of Light Emitting Diode (LED)

filaments

50a, 50b being connected in series at a second end of the filament assembly by electrically

conductive pathways

55a, 55 b.

The mandrel 30 is placed in the opening of the slip ring 40 to ensure that the slip ring 40 can slide in a direction from the top of the mandrel 30 to the base of the mandrel 30. The slip ring 40 is composed of an electrically conductive material, such as a metal, for example steel, aluminum and/or stainless steel. The slip ring 40 is in direct contact with the

conductive paths

55a, 55 b. The

conductive vias

55a, 55b may be comprised of a wire-like geometry and may be comprised of a conductive material, such as steel, aluminum, and/or stainless steel. In embodiments where the

conductive vias

55a, 55b have a wire-like geometry, the

conductive vias

55a, 55b may also be referred to as electrical leads.

The slip ring 40, which is in contact with the Light Emitting Diode (LED) filament through the

conductive pathways

55a, 55b, is positioned on the mandrel 30 such that the

LED filament

50a, 50b is substantially adjacent the sidewall of the mandrel 30, wherein the length of the

LED filament

50a, 50b positioned adjacent the mandrel 30 provides a width for the light engine 100e to pass through the opening 71 of the optical element 75. For the configuration shown in fig. 6, the width of the light engine 100e is intended to be smaller than the width of the opening 71 of the optical element 75 to enable the configuration shown in fig. 6 to be inserted into the optical element 75. For example, prior to assembly, the

LED filaments

50a, 50b are slightly tilted outward at a tilt angle of 1-5 degrees, which is the taper angle α between the central rod, i.e., mandrel 30, and the

LED filaments

50a, 50 b. However, the maximum extension (or diameter) of the filament assembly is less than the neck diameter of the bulb 75 so that the light engine can be inserted into the bulb during assembly.

Figure 6 also shows the positioning of the cap 41 over the slip ring 40 on the mandrel 30. The cap 41 has an upper surface that contacts the dome of the light bulb 75, and the length of the cap 41 is selected to contact the dome of the light bulb 75 and exert a force on the slip ring 40 to push down on the spindle 30, such as a sliding slip ring, the light engine 100' and the stem 25 are brought into engagement with the base of the light bulb 75.

The cap member 41 may be a hollow tube on which a cap is applied. The diameter of the hollow portion of the tube of the cap 41 is selected to slide over the mandrel 30 to provide sliding engagement of the cap 41 relative to the mandrel 30. The slip ring 40 is contacted by a side wall of the bottom end of the cap member 41, that is, the end having the hollow opening, opposite to the capped end of the cap member 41, and the slip ring 40 is pushed down by the cap member 41 during the installation of the light engine 100e into the bulb. The cap 41 is a hollow tube, preferably made of glass, and has a plastic coated tip that contacts the dome of the glass bulb 75 after assembly into the glass bulb 75. As the light engine projects into the bulb, the tip will be contacted by the glass bulb and pushed downward. The plastic of the tip is preferably made of resin, such as Teflon ^TM Polyvinyl fluoride.

Referring to fig. 7, a light engine 100e comprising

filament assemblies

50a, 50b connected to the stem 25 is inserted into the open end of the optical element 75. The cap 41 present above the slip ring 40 contacts the domed portion of the optical element 75, wherein as the stem 25 is brought into its seated position, the cap 41 presses down on the slip ring 40 to push the slip ring 40 down on the mandrel 30. As the light engine 100e is progressively brought into its seated position, the cap 41 depresses the slip ring 40, wherein the slip ring 40 is connected to the

conductive pathways

55a, 55b that are electrically connected to the second ends of the at least two light emitting

diode filaments

50a, 50b, causing the second ends of the LED filaments to be spaced away from the mandrel 30, while the first ends of the at least two light emitting

diode filaments

50a, 50b are secured substantially adjacent to the mandrel 30 by being connected to the

leads

76, 77. The second ends of the at least two light emitting

diode filaments

50a, 50b are pushed away from the side wall of the mandrel 30 while the first ends of the at least two light emitting

diode filaments

50a, 50b are substantially fixed via

electrical leads

76, 77 connected to the stem 25, such that the at least two

LED filaments

50a, 50b are arranged in a V-shaped geometry when the stem 25 and the optical element 75 are in the seated position. The downward movement of the cap 41 stops when the enlarged structure 43 on the spindle contacts the slip ring 40. This prevents the cap 41 from moving further downward. In some embodiments, pushing the second end of the led

filaments

50a, 50b away from the sidewall of the mandrel 30 provides a taper angle a in the range of 5 degrees to 30 degrees for a V-shaped geometry. The enhanced V-shaped geometry that provides increased under-illumination has a cone angle a (also referred to as tilt angle) that is in excess of 15 degrees and may be as large as 30 degrees. Using the enhanced V-shaped configuration shown in fig. 4, increased lumens were measurable in the-130/180/+ 135 degree region, which is the light directed toward the ground.

In some embodiments, the glass stem 25 may be sealed to an optical element 75, which is evacuated of air through the exhaust port 24 and then backfilled with a suitable highly thermally conductive mixed gas.

In summary, the sequence of assembly steps for the V-shape LE is as follows:

the automated equipment takes a V-shaped light engine configuration 100e as shown in fig. 6.

The robot inserts the structure longitudinally into the glass bulb, i.e. the optical element 75, through the available opening 71 at the bottom of the bulb.

As the V-shaped light engine structure 100e enters the bulb and moves upward, at some point the plastic tip of the cap member 41 will contact the inside top of the glass bulb dome.

Further upward movement of the mandrel 30 and cap 41 causes the slip ring 40 to compress and the V-shape of the

filaments

50a, 50b to expand to increase the cone angle a.

The V-shaped development, i.e. the increase of the cone angle a, continues until the slip ring 40 contacts the mechanical stop 43 on the spindle 30.

The angle of V is determined by the relative lengths of the

wires

55a, 55b and the

filaments

50a, 50 b.

Then, a standard glass-drop sealing process is performed to couple the stem 25 with the bulb 75.

The V-shaped geometry of the Light Emitting Diode (LED) filament provides an enhanced light distribution pattern that is not possible with light engines having Light Emitting Diode (LED) filaments arranged in an inverted V-shaped geometry. For example, the new more uniform light distribution pattern provided by a light engine having Light Emitting Diode (LED) filaments arranged in a V-shaped geometry is particularly advantageous when employed in a lamp that emits decorative light, such as red or blue or green light, or any combination thereof. This light distribution property resulting from the new light engine geometry may increase the attractiveness of decorative lighting, for example at birthday meetings, annual meetings, dance meetings, etc. This attribute is also attractive for lighting in religious situations such as halloween, easter, christmas, festivals, gloomy, gulp-bang, etc. The more uniform light distribution pattern provided by a light engine having Light Emitting Diode (LED) filaments arranged in a V-shaped geometry will now be described in more detail through data and recorded experiments.

Light distribution measurement result

Light distribution of light engine test specimens including a filament assembly with Light Emitting Diode (LED) filaments arranged in a V-shaped geometry was measured using a goniometer. Light engines including a filament assembly having at least two Light Emitting Diode (LED) filaments arranged in a V-shaped geometry have been described above with reference to fig. 1 and 2-6. For example, the light engine includes four Light Emitting Diode (LED) filaments connected in a two filament parallel and two filament series (2P2S) configuration.

Light distribution was also measured from a comparative example with the same type and number of Light Emitting Diode (LED) filaments, but in the comparative example, the light engine employed Light Emitting Diode (LED) filaments arranged in an inverted V-shaped geometry. The goniometer measures the luminous intensity (candela) of a light source as a function of angle.

FIG. 8 is a graph illustrating a comparison of luminous intensity distribution measured using a goniometer from a light engine test sample having Light Emitting Diode (LED) filaments arranged in a V-shaped geometry and a luminous intensity distribution of a comparative example of a light engine having Light Emitting Diode (LED) filaments arranged in an inverted V-shaped geometry. The curve designated by reference numeral 200 is the light intensity distribution measured from a light engine test specimen having Light Emitting Diode (LED) filaments arranged in a V-shaped geometry. The curve designated by reference numeral 300 is the light intensity distribution measured from a comparative example of a light engine having Light Emitting Diode (LED) filaments arranged in an inverted V-shaped geometry.

Fig. 9 shows how the angle on the x-axis of fig. 8 is defined. Angles higher than 130 degrees refer to the area near the lower part of the lamp (near the burner), angles lower than 45 degrees refer to the area closer to the top of the lamp, and 90 degrees refer to the center plane of the lamp.

It is observed in fig. 8 that for the V-shaped light engine geometry taught by the present invention (e.g., as shown in fig. 1 and 2-6), the luminous intensity is more uniform, as compared to an inverted V-shaped light engine configuration. Between 0 and-180 degrees and between 0 and 180 degrees of luminous intensity (candela) measured from light engine test samples with Light Emitting Diode (LED) filaments arranged in a V-shaped geometry, the two local maxima of the curve 200 are labeled 201a, 201 b. The two local maxima of the curve 300 are labeled 301a, 301b, between 0 and-180 degrees and 0 and 180 degrees of luminous intensity (candela) measured from comparative examples of light engines having Light Emitting Diode (LED) filaments arranged in an inverted V-shaped geometry. From the

maxima

201a, 201b, 301a, 301b marked on the

curves

200, 300, two angles are determined in each region whose candela differs from the local maxima by 5% or less. The difference between the two angles is an angular space where the luminous intensity is high and almost flat or uniform. The larger the angular space, the more uniform and better the luminous intensity distribution of the light engine. Table 1 shows a comparison between two light engines. It can be seen that the V-shaped light engine providing curve 200 has a uniform illumination angular space of about 50+50 or about 100 degrees, while the standard inverted V-shaped light engine providing curve 300 has a uniform angular space of about 37.5+40 or about 77.5 degrees.

Table 1: comparison of illumination uniformity

Thus, the V-shaped light engine of the present invention (as described with reference to fig. 1 and 2-7) is superior to light engines having an inverted V-shape for lighting purposes.

It should be appreciated that the use of any of the following "/", "and/or" and "at least one", for example in the case of "a/B", "a and/or B" and "at least one of a and B", is intended to encompass the selection of only the first listed option (a), or only the second listed option (B), or both options (a and B). As another example, in the case of "A, B and/C" and "at least one of A, B and C," such phrases encompass selecting only the first listed option (a), or only the second listed option (B), or only the third listed option (C), or only the first and second listed options (a and B), or only the first and third listed options (a and C), or only the second and third listed options (B and C), or all three options (a and B and C). It will be apparent to those of ordinary skill in this and related arts that this can be extended to situations where more options are listed.

Spatially relative terms, such as "front," "back," "left," "right," "clockwise," "counterclockwise," "below," "under," "lower," "over," "upper," and the like, may be used herein to facilitate describing one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

Having described preferred embodiments for light emitting diode filament lamps having a V-shaped geometry, it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments disclosed which are within the scope of the invention.

Claims

1. A light engine, comprising:

electrical leads extending into the support stem; and

a filament assembly having a V-shaped geometry electrically connected to electrical leads, comprising at least two light emitting diode filaments, wherein a first end of the filament assembly proximal to the support stem is in electrical contact with the electrical leads and provides a tip of the V-shaped geometry, and a second end of the filament assembly opposite the first end, distal to the support stem, has a second width greater than a first width of the tip; and a conductive path connecting the second ends of the at least two light emitting diode filaments.

2. The light engine of claim 1, wherein a first of the at least two light emitting diode filaments is electrically connected to an anode of the electrical lead and a second of the at least two light emitting diode filaments is electrically connected to a cathode of the electrical lead.

3. The light engine of claim 2, wherein a mandrel extends from the stem, a height of the mandrel being substantially equal to a height of the filament assembly at the second end.

4. The light engine of claim 3, wherein the conductive via has a ring geometry surrounding the mandrel and connects the second end of each of at least two light emitting diode filaments.

5. The light engine of claim 3, wherein the electrically conductive pathway comprises a straight wire-like geometry extending from a second end of a first filament of the at least two light emitting diode filaments through the mandrel to a second filament of the at least two light emitting diode filaments.

6. The light engine of claim 3, wherein the conductive via has a geometry of a ring surrounding the mandrel and connecting a second end of each of at least two light emitting diode filaments, and a straight wire-like geometry support structure extends from a second end of a first filament of at least two light emitting diode filaments through the mandrel to a second filament of at least two light emitting diode filaments.

7. The light engine of claim 1, wherein the at least two light emitting diode filaments comprise a first set of light emitting diode filaments and a second set of light emitting diode filaments, the first set of light emitting diode filaments being connected in parallel at a first end of the filament assembly to an anode of the electrical lead on a first side of the mandrel extending from the stem, the second set of light emitting diode filaments being connected in parallel at the first end of the filament assembly to a cathode of the electrical lead on a second side of the mandrel extending from the stem, the first and second sets of light emitting diode filaments being connected in series at a second end of the filament assembly by an electrically conductive path.

8. A lamp, comprising:

a lamp housing including a light projecting end and a lamp cap having an electrical connector for connection with a lamp holder;

a light engine comprising a light emitting diode located at a light projecting end of the envelope, the light engine comprising a filament assembly comprising at least two light emitting diode filaments and having a V-shaped geometry, the at least two light emitting diode filaments being connected at a first end of the filament assembly to electrical leads extending into a support stem connected to a base of the envelope, a first end of the filament assembly proximate to the support stem providing a tip of the V-shaped geometry, a second end of the filament assembly opposite the first end, distal to the support stem, having a second width greater than the first width of the tip, wherein an electrically conductive path connects the second ends of a first and a second of the at least two light emitting diode filaments; and

a driver assembly located in the lamp envelope in electrical communication with the electrical connector of the base of the lamp envelope and the electrical lead to the light engine.

9. The lamp of claim 8, wherein a first filament of the at least two light emitting diode filaments is electrically connected to an anode of the electrical lead and a second filament of the at least two light emitting diode filaments is electrically connected to a cathode of the electrical lead.

10. The lamp of claim 9, having a central axis extending from the stem, the mandrel having a height substantially equal to a height of the filament assembly at the second end.

11. The lamp of claim 10, wherein the conductive via has a ring geometry surrounding the mandrel and connects the second end of each of the at least two light emitting diode filaments.

12. The lamp of claim 10, wherein the electrically conductive path comprises a straight wire-like geometry extending from the second end of a first filament of the at least two light emitting diode filaments through the mandrel to a second filament of the at least two light emitting diode filaments.

13. The lamp of claim 8, wherein the at least two light emitting diode filaments comprise a first set of light emitting diode filaments and a second set of light emitting diode filaments, the first set of light emitting diode filaments being connected in parallel at a first end of the filament assembly to an anode of an electrical lead on a first side of a mandrel extending from the stem, the second set of light emitting diode filaments being connected in parallel at the first end of the filament assembly to a cathode of an electrical lead on a second side of a mandrel extending from the stem, the first and second sets of light emitting diode filaments being connected in series at a second end of the filament assembly by an electrically conductive path.

14. A method of assembling a lamp, comprising:

connecting a filament assembly to a support stem of a lamp, the support stem comprising a mandrel and electrical leads extending from the support stem on either side of the mandrel, the filament assembly comprising at least two light emitting diode filaments, each filament comprising a connecting conductive path from a second end of each of the at least two light emitting diode filaments to a slip ring, wherein the connecting the filament assembly to the support stem of the lamp comprises electrically connecting a first end of the at least two light emitting diode filaments to the electrical leads, the mandrel being located within an opening of the slip ring;

positioning a cap on the mandrel and over the slip ring; and

inserting the filament assembly connected to the support stem into the open end of the optical element, a cap member located above the slip ring contacting the dome portion of the optical element, wherein said contact presses down the slip ring pushing the slip ring down on the mandrel as the stem is brought to its seated position, and pushing away from the mandrel a connecting conductive path electrically connected to the second ends of the at least two light emitting diode filaments remote from said support stem, while the first ends of the at least two light emitting diode filaments close to said support stem are fixed substantially adjacent to the mandrel such that the at least two light emitting diode filaments are arranged in a V-shaped geometry when said support stem is in its seated position.

15. The method of claim 14, wherein the second separation width at the second end of the at least two light emitting diode filaments is greater than the first separation width at the first end of the at least two light emitting diode filaments.

16. The method of claim 15, wherein a first filament of the at least two light emitting diode filaments is electrically connected to an anode of the electrical lead and a second filament of the at least two light emitting diode filaments is electrically connected to a cathode of the electrical lead.

17. The method of claim 15, wherein the at least two light emitting diode filaments comprise a first set of light emitting diode filaments and a second set of light emitting diode filaments, the first set of light emitting diode filaments being connected in parallel at a first end of the filament assembly to an anode of an electrical lead on a first side of a mandrel extending from the stem, the second set of light emitting diode filaments being connected in parallel at the first end of the filament assembly to a cathode of an electrical lead on a second side of a mandrel extending from the stem, the first and second sets of light emitting diode filaments being connected in series at a second end of the filament assembly by an electrically conductive path.

18. The method of claim 15, wherein the conductive via comprises a straight wire comprised of a metal.

19. The method of claim 15, wherein the slip ring is comprised of an electrically conductive material.